Directional antenna controlled craft position plotting device



May 6, 1952 2,595,315

V. l. WEIHE DIRECTIONALANTENNA CONTROLLED CRAFT l POSITION PLOTTINGDEVICE Original Filed July 20, 1942 3 Sheets-Sheet 2 l "29 be 3 nv VENroR Vim/4M x h/f//s/f @MIM Q. AIMA.

A TTR/VEY May 6 1952 v. l. wElHE 2,595,315

DIRECTIONAL ANTENNA CONTROLLED CRAFTv POSITION PLOTTING DEVICE OriginalFiled July 20, 1942 3 Sheets-Sheet 5 :225W sume @225W :www

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A TTORNEY Patented May 6, 1952 DIRECTIONAL ANTENNA CONTROLLED CRAFTPOSITION PLOTTIN G DEVICE Vernon Weihe, Arlington, Va.

Continuation of application Serial No. 451,654, July 20, 1942. Thisapplication May 16, 1946,

Serial No. 670,087

12 Claims.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

My invention relates to radio direction finding and to the apparatusthat is to be used therewith to perform various plotting operations.

This application is a continuation of my abandoned application SerialNo. 451,654, led July 20, 1942.

(Granted under the act of March- 3, 1883, as amended April 30, 1928; 370O. G. 757) One object of my invention is to provide a simple plottingsystem with simple apparatus for radio direction nding, that willobviate the necessity for extensive calculations that have beenheretofore required.

Another object of my invention is to provide plottingr equipment anddevices that are compact and relatively light in weight, but that arecomparatively accurate, and that are constructed to permit correctingadjustments to be made without the necessity for extensive computationsthat have been heretofore necessary.

It is a further object of my invention to provide a compact remotereading azimuth indicator adapted for transferring azimuth indication toany map at any desired points inA rapid succession without mutilatingthe map.

It is a further object of my invention to provide a means for rapidlytransferring radio bearings to a map in an airplane.

The construction of the plotting devices emhodying this invention andthe manner in which they are employed and utilized for a radio nx areillustrated in the accompanying drawings, in which:

Figure 1 is a schematic and diagrammatic view of a system in which aradio direction iinder on a vehicle provides hearing indications towardtwo or more spaced radio transmitting stations in order to ascertain andto determine the x, or location, of the vehicle on which the radiodirection finder is carried:

Figure 2 is a perspective view of a set of bases for the remote readingindicating apparatus that is employed in the system as a plotting deviceas they would appear applied to a support surface, on one of which theindicating device is positioned;

Figures 3 and 4 are, respectively, plan and vertical sectional views ofa transparent plotter supporting base, of the plotting device in Figure2, together with a seit-winding measuring tape that constitutes thestraight edge;. a Figure 5 is a bottom view ofthe under surface of thetransparentbase., illustrating the parallel 2 line markings and thelocations of a centering ypin and of three positioning pins for thebase;

Figure 6 is a plan view of a yoke bracket and a flexible steel tape thatis secured thereto; and

Figure 7 is a side elevational view partly in section of the bracket andtape unit of Figure 6.

Figure 8 is a sectional view of the remote reading indicator of theradio direction finder.

Figure 9 is a plan of fragmentary plan View of the plotter base and footparts showing relation of key and keyway.

The system as illustrated in Figure 1, shows how the location of amoving vehicle, such as, for example, `an aircraft, may be ascertainedand determined on a map by reference to the known locations of thelradiating antennae of two or more spaced radiovltransmitting stations,operating at respectively diierent frequencies.

For example, two spaced radio transmitting land stations are indicatedand represented by the two antennae I6 and I I, respectively, suppliedwith radiating energy of different frequencies from their associatedtransmitting equipments I2 and I3. The two stations I0 and II areselected by the operator, or navigator of the airplane from amongavailable known land station locations that would provide most suitablelocaition bearings for the Vehicle, with` respect to the course that isto be traversed.

The bearing from the vehicle to each of lthe transmitting stations isprocured by means of a radio direction finder I4 on the vehicle, that isprovided with a directional loop antenna I5, which is rotatable about avertical axis to ascertain thedirection or bearing of a selectedtransmitting station II) or I I with reference to the airplane axis.

The movement of the directional loop antenna and its instantaneousposition are transmitted to a remote point by means of aself-synchronous system, which includes a self-synchronous generator ortransmitter I6, a self-synchronous receiver or indicator I1 which actsas a remote reading indicator of radio direction finder I 4, and aconnecting cable I8 cf conductors electrically joining theself-synchronous generator I6 and the self-synchronous indicator I'I. Asource of energy I9 is connected to the rotor or energizing unit ofself-synchronous generator I6.

Movement of the self-synchronous receiver or indicator Il is utilized toprovide an indication of the direction line. or hearing, to thetransmitting station to which the radio direction finder Itis tuned.4 Apoint of intersection between two hearing lines may be established,which will determine the f1x, or position, of the airplane with respectto these two transmitting stations.

In order to procure a geographical indication, or location, of the pointof intersection of the two bearing lines, a map 20 is employed thatcontains the locations of the two transmitting stations and the coursethat is to be traversed by the vehicle on which the radio direction nderI4 is carried.

The procedure of establishing the two bearing lines consists in settingthe indicator I1 down on the map over the point 22 marking the locationof a radio station I to which the direction finder I4 is tuned with theorigin of the indicator scale oriented on the map in the same directionas the airplane axis is oriented in space. The indicator pointer 21 thenwill have moved so as to point in the direction from the station Ill tothe position of the airplane on the map. Hence a bearing line 2I plottedon the map in -the direction in which the pointer points must passthrough the point on the map corresponding to the location of thevairplane. A repetition of the procedure using a station I I havingaldiierent location (as, for instance, at 23 in Fig. 1) and frequencydetermines similarly another bearing line 24. The airplane fix is thendetermined on the map as the point of intersection 25 of the twolbearing lines 2| and 24.

In order to impart signicance to the bearing readings the azimuth scaleof the indicator must be oriented with reference to a North-South lineon the map so thatthe zero of the azimuth scale makes an angle withNorth-South line equal to the heading of the airplane from true North.When this is done the pointer 21 then makes an angle with theNorth-South line which is the azimuth of the airplane with respect tothe radio station to which the direction iinder is tuned.

The construction of the direction finder indicator I1, which is employedin this system, is illustrated in the Figures 2 to 9, inclusive.

As shown in Figures 2 and 8 the direction nder indicator I1 comprises acylindrical housing 28 mounted on a center post 29 and free to turn on abearing 1I (Fig. 8) about the axis of center post 29. To the bottom ofcenter post 29 is rigidly attached a base or foot 32. This foot 32 is oftransparent plastic, disc-shaped, and encloses a shallow cavity 69. Thestator of a self-synchronous motor or receiver 3l is fixed to housing28, while the rotor thereof is supported on bearings coaxial with centerpost 29. The shaft 14 of the rotor passes down through an axial openingin center post 29 into cavity 69. The indicator pointer 21 attached toshaft 14 turns within cavity 59.

. The circular edge of the foot 32 has engraved thereon an azimuthscale. In the edge of foot 32k there is cut a keyway 61 for use inaligning the indicator on the map 29, as will be explained below.

. Around therim of housing 28 there is engraved an azimuth scale E4which moves against a fiducial mark 66 on centerpost 29 as housing 28 isrotated on bearingll. This fiducial mark 9B is set to mark the sameradial from the axis of centerpost 29 as does keyway 161 on foot 32.

A lock 68 is provided to lock housing 28 to centerpost 29 againstfurther turning once the angular setting of housing 28 with respect tocenterpost 23 has been made.

In addition tothe peripheral side markings 64.. the case or housingismarked on the top with two oppositely directed arrows and theassociated symbols E and W to indicate the direction of angularadjustment to compensate for variations; the side markings 64 serving toindicate the equivalent extent of the adjustment. The variables thusinvolved include the magnetic variation of the compass for the localitywhere the vehicle is operating (if the direction nding apparatusincludes an input component from a magnetic compass), and the deviationof the foreand-aft axis of the vehicle from a true Northand-South lineif, for instance, the map on the plotting table is fixed with its northside toward the head of the vehicle.

In a preferred embodiment, indicator I1 is not placed directly upon themap 20 but there are provided two or more movable supporting bases shownin detail in Figures 3-5. These bases are to be fixed tol the map overthe positions of the radio stations on which bearings are to be taken.They serve to properly position and orient indicator I1 as it is placedabout the map from station to station.

Each base 3D is preferably made of a transparent material, such as acellulose derivative, for example, so the map may be seen through thebase plate, thereby permitting the base to be properly located on themap. It simplifies such disposition for the base 39. The lbottom surfacel 36 of the base is provided with a series of engraved parallel lines 31permitting said lines to be properly aligned parallel to the North-Southmeridians on the map.

In order to permit each base to be properly positioned and centered at aselected geographical point on the map 2G, each of said bases 30 isprovided with a centering pin 38, and with three or more positioning oranchoring pins 39. The center pin 38 is slightly longer than theanchoring pins 39 to permit the base first to be positioned and centeredproperly, and then to be turned to establish the North-South alignmentbefore the base is pressed home and held in the desired iixed positionby the anchoring pins 39.

Each base 30 is further provided with a, central shallow recess or stepsocket 4I, which is encircled by a narrow annular ring, or rim 442,whose upper surface is marked with an azimuthal scale 43 throughout theentire circle. Recess 4I is dimensioned to receive snugly 'but removablyfoot 32 of indicator I1. A key 60 in rim 42 ts snugly into keyway 61 offoot 32 so that indicator I1 is locked automatically into orientationwith reference to the map meridian when it is placed upon any properlypositioned base 33.

Each base 30 is also provided with a concentric annular peripheral slot45 (Fig. 4), to accommodate and receive the arms of a yoke 33 of Figures6 and 7.

The yoke 33, as shown in Figures 6 and 7, constitutes a removable partin the form of a broken ring or fork with a central opening 46 of propersize and shape to permit the yoke to fit snugly about the body of thebase 30, with the inner side surface 41 of the yoke'engaging the innerside or wall 48 of the peripheral slot 45; The inner surface 48 of theslot, and the inner edge surface 41 of the yoke 33 coincide toconstitute part of the circle whose center 49 falls "on the'central axisof the base 30 when yoke- 33 and base 30 are assembled. The yoke 33 istherefore concentric with the base 30 throughout the movement of theyoke. The mouth or opening of the yoke is provided with two flatsurfaces 5I and 52 that are spaced slightly less than the diameter ofthe inner circle of surface 48 so that when the open end of yoke 33 .ispresented in the slot 45 and pressed slidingly thereinto, 'it must besnapped into `positibn.. and lwill then be held yieldingly on the base30 yagainst casual displacement but ,manually withdrawable, the armsyielding by moderate pulling force applied manually to the yoke. Thistype .of construction permits a yoke 33 and a .tape 34 to be entirelyremoved if two plotting devices interfere with each other when spottedon the map, and be replaced so as to avoid crowding.

The yoke,33is also .provided with two backward extending arms 53 and 54,separated by a .space 55, sufficient to receive and accommodate a fiat4base plate 56 on a shell or housing 51 for receiving the wound steeltape 34 when Vthe tape is wound, and the shell, or housing 51 is movedto its terminal position adjacent to the back arms 453 and 54 of theyoke 33. The weight of shell 51 combined with that of its base plate 53is sufficient to hold the tape extended in any position upon a map 'byrea-son of friction between the map surface and the bottom of base`plate 56. The tape is held at a xed extension by a lock, not shown,Within shell 51, which is released when the tape is to be wound orunwound by pressure on a button 62. As shown in Figure 6, one end `58 ofthe tape 34 is fixedly secured tothe yoke 33 by suitable means as tworivets 59 in such manner lthat one edge 35 of the steel tape 34 will bein direct alignment with the center 43 oi the yoke .33.

In order to more accurately align the edge 35 .of the steel tape withpointer 21 of indicator I1 when seated on the base 30, a pointer v6I isixedly secured to the yoke 33 by rivets 62 in such man- 'ner that oneedge of the pointer GI will be in direct alignment with the edge 35 ofthe tape and the center line through center of the yoke. The top of thepointer 6I extends up to and over the rim 42 of the transparent base 33,to a position `perrrlitting proper alignment of the pointer 6I with theindicating pointer 21 of indicator I1.

In .operation of my device two or more bases 39 are placed upon a map 20of the terrain over which the airplane course is to lie. As previouslyexplained each of these bases is placed with centering pin 38 prickingthe point on. the map representing a radio station. Each base 30 isturned with its azimuth scale 4.3 to agree with a polar azimuthdirection on the map and the lines 31 are aligned with the meridian onthe map nearest the station; The base r30 is then pressed down upon themap and held in place by the anchoring pins 39. It is to be .observedthat my system permits the ready use of a .map in which the meridiansare not parallel; this is a .common form of map.

In order to obtain a x the heading of the airplane is determined and isheld xed during the subsequent observations, which should be made 'in asrapid succession as possible. The heading may be read on a, magnetic orgyro compass. The airplane heading is set into indicator I? by turninghousing 2i! 'to bring the f ducal mark 653 onV center post 29 againstthe proper azimuth point .on azimuth scale 54 on 4housing .25. The eiectof this is to add the airplane heading from north onto all the readingsof the radio direction finder indicator. Once the heading has been setinto the indicator, the setting is locked in by means of lock 68. f y

The indicator I1 is then seated upon a first baseSIl `which is centeredupon the position on the :mapof a rst radio. station. Direction nder I4is then tuned and oriented to the Astation concerned. The needle 21 ofindicator I1 thereby turns automatically so :as to point from thestation to the airplane position on the map. Yoke 33 is then` turned byhand so that pointer v6I is aligned with needle 21. -Tape 34 is thenunwound and left in position during the remainder of the observation.

The construction by which gpointer 6I is brought almost in contact withneedle 21 makes possible the transfer of angle reading from indicator:I1 to tape 34 and to the map Vwith a minimum of error. When aligned thetip of pointer BI nearly touches the tip of needle 21. It is yproposedto call this method of alignment, alignment by coincidence.

Indicator I1 is next removed from the first base 30 and placed on asecond base 30, which marks .the location of a second radio station onthe map. Radio direction nder I4 is then tuned and oriented to thissecond station. Yoke 33 of the second base 30 is turned to the directionnow indicated by needle .21, which is the direction from the `secondstation to the airplane. The tape 34 is .unwound upon a map, and thepoint of intersection of its edge 35 with the edge 35 of the first tape.34 marks the location of the airplane :on the map 20.

The advantages of the simplicity of the present invention become`apparent from consideration of the factors necessary to take and toplot a radio bearing in aircraft, namely:

alors-@alfiere "The device herein described eliminates the abovecalculations and observations d, f, h, y, and .7a. Bearing of plane fromstation (l) is obtained 'by satisfying the conditions a, b, c, y, andCorrection for e is accomplished automatically in standard` U. S. Armyradio compass equipment, and i 'is neglected except for bearings ofseveral hundred miles .or more.

The transparent bases by reason of their transparency do not interferewith normal use of .the map.

The graduated folding or winding rules show approximate distances alongeach bearing line, and permit the use of a multiplicity of plotter baseswithout the interference which would result from the use of rigidstraight edges. However, it is within the scope of my invention to userigid straight edges where preferred.

The'plotter bases are usable alone as manual plotting devices or asmovable compass roses with graduated straight edge. Their use alone isvery practicable as the result of their (l) transparency, V(2)compactness, (3) light weight, and (4) desirable length, and utility ofthe extended grad- Yuated scale. V

kThe special apparatus used in my system,

namely, the bases, plotter and rules may be made ,'.Vry compact, s o asto be readily stored away in an .airplane When not in use. No specialmap is required andnospecial table .on whichl .to lay In accordance Withthe provisions of the patent statutes I have herein described theapparatus and principles of operation of my invention, but I desire tohave it understood that the apparatus shown is only illustrative andthat the invention may be carried out by other means. Also, While it isdesigned to use the various features and elements in the combination andrelations described, some of these may be altered and others omittedwithout interfering with the more general results outlined, and theinvention extends to such use.

I claim:

l. A navigationplotting device comprising, a transparent protractorsupporting base provided with parallel line markings on the central areaand with an azimuth scale around the rim, a self-synchronous receiverunit adapted to be removably and coaxially supported on said base, saidreceiver unit embodying a stator winding, a rotor free to orient itselfwith respect to a magnetic iiux field to be set up by the stator windingand an indicating pointer on the rotor to indicate the rotor positionrelative to the azimuth scale on said base, a housing for said receiverunit, positioning means on said housing coupling with said base toassure and to maintain proper azimuthal alignment of said housing andbase. a movable peripheral bracket fitting into a concentric annularslot disposed peripherally around the rim of said base, the brackethaving secured thereto an inwardly directed pointer for alignment withthe indicating pointer, and a selfwinding tape measure fixed to saidbracket with one edge of the tape measure radially aligned with thepointer axis and with the center of said base, so that said tape measureedge will constitute a radius and bearing line through the center ofsaid base.

2. A navigation plotting device comprising a transparent circularprotractor supporting base provided with parallel line markings on thecentral area and with an azimuth scale around the rim, a center postremovably secured coaxially and in xed orientation to the base, aself-synchronous receiver coaxially supported on the center post, saidreceiver comprising a rotor with an indicating pointer suspendedtherefrom coaxial with the base to indicate the position of the rotorrelative to said azimuth scale, a straight-edge, and means to pivotallyand radially connect said straight-edge to the base and provided with apointer that is alignable with the indicating pointer of the rotor topermit the straight-edge to be directly aligned with the indicatingpointer.

3. Navigation plotting apparatus comprising, a transparent circular baseprovided with a center positioning pin and at least one anchoring pin tohold said base as positioned, a measuring tape having one end removablysecured to said base and pivotally disposed relative to the center ofsaid base with one edge of said tape `radially aligned with the centerof said base, a remote registering azimuth indicator, said indicatorincluding a rotor and an indicating pointer to indicate its position,means on the base and the indicator for permitting said indicator to beremovably placed and azimuthally oriented on said base, and aligningmeans whereby the tape is aligned with the indicating pointer toestablish l a line of bearing.

4. A navigation plotting device comprising a transparent base having acentral positioning pin and at least one co-operating anchoring pinsecured thereto, a shallow concentric recess on the top thereof toaccommodate a direction indicator in unique angular relation thereto anda peripheral annular concentric slot, a bracket shaped as a bifurcatedyoke to fit into the annular slot of said base and with the centralopening of the yoke having a circular contour adapted to closely fit theannular slot of the base so that the yoke will be concentricallyangularly adjustable around the base, and a flexible measuring tapesecured to the bracket to measure from the center of the base, one edgeof the tape providing an extension of a radius of the base. o

5. A navigation plotting device as defined in claim 4, including apointer located within the shallow recess of said base to provide, withthe center of the base, a locus for a line of bearing to be laid outbythe edge of the tape, and said direction indicator including means forcontrolling the position of the pointer to establish a direction line toa point Whose position or bearing is to be ascertained,

6. Plotting apparatus for a map, including a inap-engaging supportingbase positionable selectively upon a precise point of said map, andincluding a center axis means to X the base in precise angular positionrelative to a polar direction at the selected point as a center ofrotation, a remote reading azimuth indicator having a body stator partconcentric with said center axis and a concentric remotely controlleddirectionindicating rotor, said base and body stator having separablesocket and key means coaxial with said center axis means and said rotorconstructed to allow said indicator body stator part to be removably setupon and lifted at will from said base, said socket and key meansconstructed to hold the stator part in precise orientation relative tosaid base and map, and discrete coincidence means on said base fortransferring the azimuth reading of the indicator xedly onto the map asa line member extending from adjacent and aligned with saidselectedpoint across the map.

7. A navigation plotting device comprising a transparent supporting basewith a circular protractor marking, a revoluble bracket thereonrotatable about the axis of the base and having a radial fork havinghorizontally spaced bifurcations spaced above and parallel to the planeof the bottom face of the base, and a straight edge elementconsistingvof a reel case having a at base plate slidable under saidfurcations close 'to said base, said case adapted to lie over saidfurcations, and an extensible tape reelable in the case and having itsextremity attached to said racket extending across said marking on thease.

8. A navigation plotting device comprising a transparent base plate witha circular protractor marking, said plate having a top socket thereinconcentric with said marking, to 'receive freely and separably steppedtherein a remotely controlled pointer, means on the plate constituting acircular body concentric with the protractor scale, a semi-flexibleresilient arcuate bracket around and rotatable freely on said body, itsopening being of less width at its entrance than the diameter of thesaid body, and manually and slidably removable therefrom by virtue ofits flexibility, and a straight-edgeelement consisting of a windablesteel tape having itsfree end secured to said arcuate bracket in suchmanner that one edge of the steel tape is in alignment withthe centerroi thebase.` plate, 'and a winding device attached to the tape andmovable therealong to and from the base.

9. A navigation plotting device as dened in claim 4, including saiddirection indicator, the latter comprising a pointer rotatable Withinthe shallow recess to provide, with the center of said base, a locus fora line of bearing to be laid out by the edge of the tape.

10. In a radio controlled direction indicator for navigational use onmaps and the like, a plurality of separate independently movablesupporting bases, means on said bases to separably attach them to theface of a map or the like at points on the map selected at Willcorresponding to geographical positions of respective radiotransmitters, a motor having a'rotor responsive to electrical azimuthdata separably andV alternatively mounted on one of said bases, adirection line member on each said base extendable to form a bearingline from the base in accordance with a position of said rotor when themetor is set on the base, and mounting means on each base constructed sothat the motor may be placed upon one of the bases an azimuth bearingline obtained and then moved to another of saidbases to obtain anotherazimuth bearing line, With a single motor instrument, and the severalbearing indications retained on the map by said line members afterremoval of said motor, whereby the intersection of two such bearinglines Will present the geographical position at the point ofobservation.

11. In a radio direction nding position indicating and position plottingapparatus, a plurality of transparent bases, each provided with securingmeans to separably engage a map, a bracket coaxially and pivotallysupported on each said base, each bracket provided with a selfawindingtape having one end revolubly secured'to the bracket so that one edge ofthe tape is aligned radially with the center of said base, a'pointerdevice separably mounted coaxially on said base responsive todirectional control data electrically transmitted thereto, said pointerdevice adapted to be placed in turn at Will on each of said bases toestablish at each base a directional indi-cation of a bearing line fromdata transmitted to said pointer device and means for holding each ofsaid tapes in extended position so that extended tapes may representlines of bearing to mutually determine a geographical location on a map.

12. A navigation plotting Ydevice for deter- 10 mining positions of acraft on a map, comprising a substantially flat transparent base memberhaving a center indicating element at its underside, and having a broadsocket recess in its upper side concentric with said center indicatingelement, said recess having a key part therein, a direction indicatingself-synchronous receiver unit separably engaged with the basecomprising a foot member shaped to t and liftably set in said recesswith the unit in stable equilibrium, lifta-ble atwill therefrom, andhaving a key part coengaged with the first named key part at apredetermined angular position of the foot member around said centerindicating Velement on the base, one of said two named members at leasthaving an azimuth indication thereon, a selfsynchronous motor mounted onsaid foot member on a vertical axis coincident with said centerindieating element and including a stator adjustable angularly on thefoot member around said axis, means on the foot member and stator toindicate azimuth positions of the two relatively to each other, means tosecure the stator releasably in adjusted azimuth positions on the footmember, and an azimuth indicating pointer connected with the rotormovable therewith adjacent the foot member.

VERNON I. WEIHE.

REFERENCES CITED The following references are of record in the ille ofthis patent:

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